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Could Food Intolerance be affecting your Fitness?

Could Food Intolerance be affecting your Fitness?

4 minute read time

What is food intolerance?

It is estimated that food intolerance affects 45 per cent of the population^ and, while the condition is not life threatening, it can have a detrimental effect on health and fitness. As such, it is a key consideration when planning what to eat to stay fit.

Intolerance to certain foods or food groups puts a strain on the gut and this stress can lead to large food particles entering the blood stream. The presence of these particles in the blood could trigger an immune response, which may result in bloating, fatigue, headache or weight gain.

If you’ve been managing your gym food plan carefully but still found yourself asking ‘why do I feel so tired and weak?’, there’s a chance you could be suffering from a food intolerance. Before pursuing this further, it is important to first rule out any potential underlying health conditions by visiting your doctor.

What are some signs and symptoms of food intolerance?

The effects and symptoms of food intolerance are wide-ranging and this can make it difficult to distinguish diet-related problems from other health issues.

Even if you are eating healthy food, intolerance to food and drink ingredients could potentially bring about digestive, dermatological, neurological, musculoskeletal and psychological conditions, leading to symptoms that may have a negative impact on sporting performance and fitness. Scientific Director at yorktest, Dr Gill Hart, has explored this link in more depth in one of her published white papers.

Some common symptoms of food intolerance are:


The fact that we all eat a variety of foods from meal to meal makes it hard to identify the root cause of a diet-related problem. To further complicate matters, the symptoms of intolerance can take a lot longer to surface than those of food allergies. While food allergies typically cause a reaction within two hours of eating, it can take up to 72 hours for the effects of intolerances to occur.

This means that self-diagnosis of food intolerance* can be challenging and some athletes and sporting professionals choose to undergo tests under the expert guidance of nutritional therapists.

Example problem foods related to intolerance

The food that people are intolerant to varies widely. Some people may have a food intolerance* to wheat, gluten, milk and fruit and vegetables, whilst others could experience problems related to the digestion of dairy products, eggs and chocolate.

If you experience signs of bloating or fatigue after eating any of the foods listed above, it’s quite possible you are experiencing a food intolerance and may need to adjust your fitness food plan.

fitness and food intolerance

How do you test for food intolerance?

One effective and efficient way to establish whether your body is having an adverse reaction to something in your diet is a food-specific test.

The IgG antibody test has been specially developed by yorktest to identify the foods to which your body is reacting. Raised levels of food-specific IgG antibodies in the blood can effectively indicate an intolerance to a specific ingredient.

The test is carried out by an experienced laboratory team, overseen by Scientific Director, Dr Gill Hart. It requires you to obtain a finger prick blood sample, which can easily be taken by yourself in the comfort of your own home using the simple kit provided. You’ll then receive comprehensive post-test support from the yorktest team.

The results of the test allow you to eliminate problem foods and replace them with nutritional alternatives, which will ensure that your diet contains all the necessary nutritional requirements for fitness.

Case studies

We have worked with customers who have experienced a broad range of symptoms related to food intolerances*. You can read our case studies to find out how intolerance tests* helped them to address bloating and fatigue, and digestive problems.

Even the world’s leading athletes can be susceptible to food intolerance*; a recent yorktest trial with Wigan Warriors Rugby League club found symptoms in a number of players, who were then able to improve their performance by adjusting their diets.

Having reached the pinnacle of your chosen field doesn’t necessarily mean you know what to eat to stay fit – Rotherham United footballer, Ryan Williams, is another sports star to have benefitted from the IgG antibody test.

Further reading

To gain a deeper understanding of food intolerance, natural fitness food and the causes of extreme fatigue, you may also be interested in reading:

The difference between allergies and intolerances – these are often confused but there’s a big difference between food allergy and food intolerance.

Common digestive problems – Digestive issues can be a sign of a serious condition and have also been associated with food intolerance.

The relationship between weight gain and food intolerance – How much of an impact can a food intolerance have on our weight? Find out here.

Help and support

If you experience any of the symptoms of food intolerance, we advise that you speak to your GP first before taking any further steps yourself. For more information on our services, please contact our friendly Customer Care team.

*yorktest define food intolerance as a food-specific IgG reaction.

^ According to research carried out by Allergy UK


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